New American Idol judge Jennifer Lopez, who just released her new album Love? this past Tuesday, got the party started on the competitive reality TV show American Idol last night with a surprisingly vigorous performance of her single On the Floor. J. Lo was joined by rapper Pitbull (who guests on the track) for last night’s performance and she truly exhibited a return to form on the stage. In recent years, Lopez‘s performance style has been very lackluster (you may recall J. Lo fell on her ass during a sad performance at the 2009 American Music Awards) but with her new album (buoyed by her new job on Idol), it looks like Jenny from the Block is back as a serious pop star. Watch video of her full performance below.

Jennifer Lopez smashed two dancers out of glass cases, performed on a platform as it rose from the stage and dropped to the floor in a complex choreographed dance routine while performing her RedOne-produced single “On the Floor.” She was joined by Miami rapper Pitbull, who first emerged from the crowd and later appeared onstage and via the mobile staircase at the back of the “Idol” set … Wearing a glimmering ensemble that included a revealing top and what looked like modified Hammer pants (they were tight on the legs and baggy in the middle), J.Lo worked the stage while lasers shot around the studio and bursts of pyro erupted around her. The performance was timed to coincide with her new album Love?, which hit stores this week and as of Thursday night was #6 on the iTunes albums chart. Earlier this week, Lopez teased the performance to MTV News. “You can expect some fun; I don’t want to give away too much. But you know we’re gonna go out there, we’re gonna do our thing,” she told us on Tuesday. “It’s going to be a lot of fun. I don’t even want to tell you what song we’re doing, I just want you to watch.” Although every effort was made to present the performance as if it were live — following the song, Lopez was absent from the judges’ table, and host Ryan Seacrest explained she was backstage changing her clothes — some sloppy editing (namely a safety bar on the riser that continuously appeared and disappeared throughout the performance) made it apparent the routine was taped in advance of the episode.

Pre-taped or not, the performance was hot! Last night’s performance by Jennifer Lopez really reminded me of her glory days when she ruled the popcharts with her first 3 albums. These days, there is a whole new crop of female performers that are really working it out in order to define the landscape of pop music right now … but last night, J. Lo officially threw her hat into the ring to remind everyone that she not only still has it but she’s going to use it as well. It remains to be seen if Jennifer Lopez is going to continue to giving us performances like this and make a serious go of her pop music career again but I really enjoyed watching this performance last night. I miss the old J. Lo, it was nice to see her back in action if only for one night. So … what did y’all think of J. Lo‘s performance? Did she kill it? Did you enjoy seeing her back in action again?

The song is perfect JLo, hopefully it will be a bit hit for her, but she looked a mess in her outfit & hair. And she’s got to practice her shout-out voice, she just sounded weak & out of breath. I KNOW she’s dancing her butt off but if you can’t sing or talk while dancing: don’t do it, just dance & lip-sync.

god i love me some JLO. it was a great performance. and i even bought the new cd. its good, reminds me why i became a fan in the first place.
i have a feeling 2011 is going to be a great year for Jenny.

Exactly! I hated the pants. The performance was great. Glad she danced more than what she did in the video. The hot men in the glass boxes were cool, especially when she broke them free. But, come on, the pants were just horrible! What was she thinking?

Meh. It would have helped if the crotch of her pants weren’t half way to her knees. If this is a trend, I hope it dies quickly because the dirty baby diaper look just isn’t hot. As far as singing live goes…I don’t think so except during the parts where she hollered out the names of cities – the rest was lipsynched. I did love Pitbull though. Loved what he was wearing and his general presence.